Detergent composition containing organic phosphonate corrosion inhibitors



United States Patent 3,351,558 DETERGENT COMPOSITION CONTAINING ORGANIC PHOSPHONATE CORROSION INHIBITORS Roger Earl Zimmerer, Springfield Township, Hamilton County, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio No Drawing. Filed Sept. 6, 1966, Ser. No. 577,149 10 Claims. (Cl. 252137) ABSTRACT OF THE DISCLOSURE This application is a continuation-in-part of my copending application Ser. No. 315,678, now abandoned, filed Oct. 11, 1963.

This invention relates to detergent compositions comprising certain detergent builders which are very corrosive towards aluminum, German silver and Zamac. Specifically, this invention relates to detergent compositions which have been inhibited against the corrosion of Zamac and, optionally, aluminum and/ or Germany silver by the presence of certain corrosion inhibitors including specific organic phosphonate corrosion inhibitors.

Detergent builders (chelating materials) tend to corrode aluminum, Genman silver and Zamac when the detergency builders come in contact with these materials in washing machines, dish pans, kitchen equipment, sinks and the like. (Zamac is a common alloy containing zinc which is particularly used in washing machine pumps. Zamac is a zinc alloy containing, e.g., 4% aluminum, 0.04% magnesium, balance zinc. Zamac #3, the most commonly used Zamac, is described on page 1169 of Metals Handbook, 8th ed., vol. I, published by the American Society for Metals.) This corrosion problem has commonly been solved with respect to aluminum and German silver by including in detergent compositions containing detergency builders, alkali metal silicates such as sodium silicate having a ratio of SiO :Na O of about 1.6 and a German silver corrosion inhibitor such as benzotriazole. The alkali silicates are extremely eflicient with respect to preventing the corrosion of aluminum and the benzotriazole is very efficient with respect to preventing the corrosion of German silver. Furthermore, they are relatively inexpensive in effective amounts. However, the sodium silicate and benzotriazole do not prevent these compositions from corroding Zamac and when certain very effective detergency builders and chelating agents such as sodium nitrilotriacetate are present in detergent compositions this Zamac corrosion is completely unacceptable. Therefore, it is necessary to include in such compositions a corrosion inhibitor which will prevent the corrosion of the Zamac especially when the compositions contain the more effective detergency builders such as sodium nitrilotriacetate.

Accordingly, it is an object of this invention to proice vide a detergent composition containing certain specified detergency builders, said detergent composition being effectively inhibited against the corrosion of Zamac and, optionally, aluminum and/or German silver by the presence of certain corrosion inhibitor compounds.

The preceding object and other objects can be achieved by providing a detergent composition comprising (1) from 1% to 98% of the composition of a detergency builder selected from the group consisting of watersoluble amino polycarboxylate, tripolyphosphate and polyphosphonate detergency builders and mixtures thereof; and

(2) more than about 0.05% and less than about 25% of the total detergent composition of a corrosion inhibiting compound having the formula wherein R is selected from the group consisting of (l) a straight alkyl chain with the phosphorus atom attached to secondary carbon atoms on the chain, said straight chain alkyl radical containing from about 12 to about 24 carbon atoms and (2) straight chain alkyl benzyl groups wherein the alkyl group contains from about 9 to about 18 carbon atoms and wherein Q is a water-solubilizing cation, said detergent composition being inhibited with respect to the corrosion of Zamac. Alkyl, as used herein, includes saturated and unsaturated alkyl groups.

'The detergent compositions of this invention preferably consist essentially of:

(1) from about 1% to about of the composition of a detergency builder selected from the group consisting of Water-soluble amino polycarboxylates, tripolyphosphates, polyphosphonates and mixtures thereof;

(2) from 0% to about 15% by weight of the composition of an alkali metal silicate having a ratio of SiO :M O of from about 1.0 to about 3.6, preferably 1.6 to 3.2, (M in the above ratio is selected from the group consisting of potassium and sodium);

(3) more than about 0.5% and less than about 25% by weight of the total detergent composition of a corrosion inhibiting compound having the formula wherein R is selected from the group consisting of (1) a straight alkyl chain radical with the phosphorus atom attached to secondary carbon atoms on the chain, said straight chain alkyl radical containing from about 12 to about 24 carbon atoms and (2) straight chain alkyl benzyl groups wherein the alkyl group contains from about 9 to about 18 carbon atoms and wherein Q is a water-solubilizing cation, e.g., a cation selected from the group consisting of hydrogen, alkali metal, ammonium and substituted ammonium cations;

(4) from 0% to about 1%, preferably 0.02%, of a corrosion inhibiting compound for the protection of German silver;

(5) from 0% to about 40% of an organic detergent selected from the group consisting of nonionic, anionic, amphoteric, and zwitterionic detergents, and mixtures thereof;

(6) from about 0% to about 90% of other detergency builders selected from the group consisting of alkali metal pyrophosphates, orthophosphates, perborates, tetraborates, hexaphosphates, sesquicarbonates, and bicarbonates and mixtures thereof; and

(7) from 0% to about 90% water.

Typical amino polycarboxylate detergency builders include alkali metal (sodium, potassium, etc.), ammonium and substituted ammonium (substituted ammonium, as used herein, includes mono-, diand triethanol ammonium cations) salts of the following acids: ethylenediaminetetraacetic acid, N (2 hydroxyethyl)-ethylenediaminetriacetic acid, N-(2-hydroxyethyl)-nitrilodiacetic acid, diethylenetriaminepentaacetic acid, 1,2 diarninocyclohexanetetraacetic acid and nitrilotriacetic acid. The above amino polycarboxylate detergency builders are amino poly'acetates. The trisodium salts of the above compounds are commonly used. The water soluble salts of nitrilotriacetic acid will hereinafter be referred to as NTA, and the water-soluble salts of ethylenediaminetetraacetic acid will hereinafter be referred to as EDTA.

Polyphosphonates are also valuable builders in terms of the present invention including specifically sodium and potassium salts of methylene diphosphonic acid, sodium and potassium salts of ethylene diphosphonic acid, sodium and potassium salts of ethane-l-hydroxy-l,1-diphosphonic acid and sodium and potassium salts of ethane-1,1,2-triphosphonic acid. Other examples include the water-soluble (sodium, potassium, ammonium, etc.) salts of ethane- 2-carboxy-1,1-diphosphonic acid, hydroxyrnethanediphosphonic acid, carbonyldiphosphonic acid, ethane-l-hydrxy-1,1,2-triphosphonic acid, ethane-Z-hydroxy-1,1,2-triphosphonic acid, propane-1,1,3,3-tetraphosphonic acid, propane-l,1,2,3-tetraphosphonic acid, and propane-1,2,2, 3-tetraphosphonic acid.

Examples of the above polyphosphonic compounds are disclosed in US. Patents 3,159,581 and 3,213,030 and US. patent applications, Ser. No. 266,055, filed Mar. 18, 1963; Ser. No. 368,419, now abandoned, filed May 18, 1964; Ser. No. 517,073, filed Dec. 28, 1965; Ser. No. 507,- 662, filed Nov. 15, 1965; and Ser. No. 489,687, filed Sept. 23, 1965.

Other suitable detergency builders include sodium and potassium tripolyphosphates.

These detergency builder compounds normally make up from about 1% to about 90%, preferably from about to about 60%, of the composition. The detergency builder compounds are preferably present in a ratio of detergency builder compounds to any detergent surfactant used in the composition of from about 1:2 to about 10:1. These detergency builder compounds attack aluminum, German silver and Zamac when applied as aqueous solutions to these metals.

The silicate corrosion inhibitor defined hereinbefore is the typical corrosion inhibitor which is well known to those skilled in the art. It'can be present in the detergency compositions of this invention in an amount from about 1% to about preferably from about 2% to about 10%. A typical silicate corrosion inhibitor is sodium silicate having an SiO :Na O ratio of about 1.6. This silicate corrosion inhibitor prevents the corrosion of .aluminum but 'is essentially ineffective in preventing or substantially reducing the "corrosion of zinc alloys such as Zamac by, e.g., NTA regardless of the level at which the silicate corrosion inhibitor 'is used.The silicate corrosion inhibitor is an essential ingredient in the preparation of a general purpose detergent composition at the least cost since the phosphonate corrosion inhibitor is not effective in preventing the corrosion of aluminum and German 'silver at levels below about 2% as specified hereinafter. The phosphonate is more expensive than silicate.

The phosphonate corrosion inhibitors which contain more carbon atoms will prevent the corrosion of aluminum and German silver-in addition to Zamac when used at higher levels, e.g., above about 2%. However, in some cases, it would be unduly expensive to provide sufficient phosphonate corrosion inhibitor 'for this purpose. Therefore, some silicate corrosion inhibitor is always preferred for general purpose detergents for inhibition of aluminum corrosion, although with larger amounts of higher molecular Weight phosphonate corrosion inhibitors, silicate is an optional ingredient insofar as aluminum corrosion is concerned.

The phosphonate corrosion inhibitors which are effective at higher levels in inhibiting the corrosion of aluminum in addition to Zamac are those alkyl phosphonates and phosphonic acids wherein the alkyl group contains at least about 18 carbon atoms and alkyl benzyl phosphonates and phosphonic acids wherein alkyl benzyl groups contain at least about 20 carbon atoms. These larger, more effective phosphonate corrosion inhibitors, when used at levels above about 2%, preferably from about 2% to about 6%, inhibit the corrosion of aluminum and German silver by the effective detergency builders described hereinbefore. If there are less than about 18 carbon atoms in the hydrophobic group, the inhibition film, hereinafter described, will not prevent the sequestering builders, e.g., STP, from reaching the metal surface to corrode it. If there are more than about 24 carbon atoms in the hydrophobic group, the solubility of the molecule is lessened and undesired precipitation by free calcium and magnesium ions occurs at lower and less acceptable concentrations.

Although it is not desired to be bound by theory, it is believed that the choice of the detergency builders with which the phosphonate corrosion inhibitors of this invention are uniquely effective at higher levels in preventing the corrosion of aluminum is dependent upon two factors. The first factor relates to the efficiency of the detergency builder in sequestering the alkaline earth metal ions, e.g., calcium ions, present in hard water. If the free (not sequestered) calcium ion concentration in the builder solution is sufficiently large to insolubilize the corrosion inhibiting compounds by forming the calcium salt, then the corrosion inhibiting properties of the compounds are destroyed. Builders such as sodium orthophosphate apparently do not sequester calcium ions sufficiently to prevent insolubilization of the corrosion inhibiting compounds. Apparently the corrosion inhibiting compounds must be soluble to be etfective. The second factor relates to the size of the detergency builder molecule. Apparently, if the builder molecule is too small (e.g., the alkali metal pyrophosphate builder salts) then it will slip through the film of corrosion inhibitor as hereinafter more fully described. The tripolyphosphate, polyphosphonate, and aminopolycarboxylate builders used in the compositions of this invention have 'suflicient sequestering properties to maintain proper inhibitor solubility and sufficient molecular bulk to permit proper inhibition.

Although again it is not desired to be bound by theory, it is also believed that the corrosion inhibitors of the present invention are effective with respect to the inhibition of corrosion of Zamac, aluminum, and German silver because the hydrophobic group '(R-) is attached to the 'hydrophilic group 3 when) in a bulky manner. This bulkiness is achievedin several ways. For example, a straight chain alkyl hydrophobic portion (R-) of the corrosion inhibiting compound is attached to the hydrophilic group through a secondary carbon atom. Similarly, bulkiness is achieved by incorporating an aryl group such as a benzyl group into the hydrophobic group. The alkyl chains can contain a certain amount of unsaturation and/or branching. Similarly, the presence of some l-isomer is acceptable and, in fact, a random phosphonate is preferred. Random refers to an essentially even distribution of isomers. In some instances there will be essentially no l-isomer and in other instances there may be a slightly greater amount of l-isomer than would be present in a completely random distribution as a result of the processes used in preparing the phosphonates.

Apparently, the most important results of this bulky attachment is to increase the solubility of the compounds in water, especially in the form of their alkaline earth metal (e.g., calcium and magnesium) salts. The bulkier attachments, for example, where the hydrophilic group is attached near the center of straight alkyl chains are therefore preferred. If the corrosion inhibiting compound is not sufiiciently soluble, then the compound will precipitate in the presence of free calcium and magnesium ions prior to forming the protective film on the metal. Corrosion inhibitors wherein the phosphonate or phosphate group is attached to a relatively unbranched (straight chain) hydrophobic group at a terminal position precipitate in the presence of free calcium and magnesium and hence cannot form a sufficiently tenacious film to prevent the sequestering builders, e.g., STP, from reaching the surface.

The phosphonate corrosion inhibitors of this invention can be prepared in several ways. For example, phosphorus trichloride, oxygen and a paraffin containing about 18 carbon atoms can be reacted together and the reaction product hydrolyzed to give the phosphonic acid.

Other methods of preparing these phosphonates are set forth in US. Patent 2,724,718, the references referred to therein and the copending parent application, Ser. No. 315,678, filed Oct. 11, 1963.

Specific examples of the above compounds include:

Randomly phosphonated octadecane such as the product prepared by reacting diisopropyl phosphite with a random olefin containing an average of 18 carbon atoms in the presence of a free radical initiator and thereafter pyrolyzing the phosphonate ester to give the phosphonic acid.

Other examples of phosphonate corrosion inhibitors include:

The following compounds and the sodium, potassium, ammonium, monoethanolammonium, diethanolammonium and triethanalammonium salts thereof:

lO-Nondecylp-hosphonic acid;

Pentadecylbenzylphosphonic acid;

Alkylbenzylphosphonic acid mixtures wherein the alkyl groups can be derived from (1) a mixture of propylene polymers, (2) olefins derived from cracked petroleum Waxes, or (3) olefins displaced from Ziegler-type buildup reactions of ethylene, said alkyl groups ranging in size from 12 to 21 carbon atoms and averaging from about 14 to 18 carbon atoms;

Hexadecylbenzylphosphonic acid wherein the hexadecyl group is derived from polymerized isobutylene;

Alkylbenzylphosphonic acids wherein the alkyl group is derived from a chlorinated kerosene fraction averaging from about 15 to about 18 carbon atoms;

The mixture of 6-eicosenyl-4-phosphonic acid and 5- vinyl octadecyl-4-phosphonic acid obtained by reducing the ketone obtained from the reaction between butyric acid anhydride and the allylic carbmion of l-hexadecene to the alcohol, conversion of the alcohol to the tosyl ester, alkylation of dibutyl phosphonate anion with the ester, and hydrolysis of the resulting product; 7

The hydrolyzed reaction products of phosphorus trichloride, oxygen, and a mixture of olefins containing from about 18 to about 25 carbon atoms and which can be derived from 1) cracked petroleum waxes or (2) Ziegler-type build-up reactions of ethylene (these hydrolyzed reaction products are a mixture of saturated and unsaturated phosphonic acids and saturated alkyl phosphates, some of the saturated phosphonic acids contain bound chlorine);

The mixture of octadecylphosphonic acids prepared by alkylating dibutyl phosphonate anion with the mixture of 2- through 9-octadecyl sulfuric acids obtained by reacting l-octadecene with excess sulfuric acid at 0-10 C. for about two to three hours and hydrolyzing the alkylated dibutyl phosphonate anion (this product is a random octadecylphosphonic acid containing a mixture of 2-9 isomers);

The mixture of phosphonic acids produced by first isomerizing the double bond of l-octadecene with aluminum chloride, adding sodium hypophosphate to the resulting olefins and oxidizing the resulting phosphinates to phosphonates with nitric acid (this product is random octadecylphosphonic acid containing a mixture of 2-9 isomers);

The hydrolyzed reaction product of l-octadecene, phosphorus trichlon'de and oxygen (these hydrolyzed reaction products are a mixture of saturated and unsaturated phosphonic acids and saturated alkyl phosphates, some of the saturated phosphonic acids contain bound chlorine);

The hydrolyzed reaction product of l-octadecene, phosphorus trichloride, acetic anhydride and oxygen (this hydrolyzed reaction product is a mixture of saturated and unsaturated octadecylphosphonic acids and saturated octadecylphosphates, some of the saturated phosphonic acids contain bound chlorine); and

The hydrolyzed reaction product of octadecane, phosphorus trichloride and oxygen (this hydrolyzed reaction product is a random octadecylphosphonic acid containing a mixture of 1-9 isomers).

(The last six corrosion inhibiting compounds listed above and described as reaction products are complex mixtures of what are primarily, i.e. at least phosphonates wherein said phosphonate groups are attached to the hydrophobic chain through secondary carbon atoms.)

The phosphonate corrosion inhibitors of this invention are effective at preventing the corrosion of Zamac in extremely small amounts (more than 0.05% and less than 2%, preferably about 0.1%) whereas the corresponding phosphates and, especially, phosphonate esters are relatively ineffective, when used at the same levels. Also, phosphates and phosphonate esters are much less eifective in preventing the corrosion of aluminum when used in amounts above about 2%. The mixture of silicate corrosion inhibitor and phosphonate corrosion inhibitors is more effective than the phosphonate corrosion inhibitor alone in the protection of Zamac. Similarly, the mixture of silicate corrosion inhibtor and phosphonate corrosion inhibitor are more effective than either alone in the protection of aluminum. This is particularly true With respect to die cast aluminum.

The corrosion inhibitors effective against German silver are exemplified by benzotriazole. Many other examples of effective compounds are disclosed in US. Patents 2,618,603, 2,618,605, 2,618,606, and 2,618,608. If substantial amounts of, e.g. alkali metal perborate salts are present in the composition the German silver corrosion inhibitor is not required.

The corrosion inhibitors of this invention are effective in the presence of a wide variety of detergent surfactants Which are optionally utilized with the detergency builders. These detergent surfactants are present in an amount from 0% to about 40%, preferably from about 10% to about 20% of the detergent composition. Examples of detergent surfactants which can be used include:

1) Ordinary alkali metal soaps such as the sodium and potassium salts of the higher fatty acids of naturally occurring plant or animal esters (e.g., palm oil, coconut oil, babassu oil, soybean oil, castor oil, tallow, Whale and fish oils, grease and lard, and mixtures thereof) or of synthetically produced fatty acids (e.g., rosin and those resin acids in tall oil) and/or of naphthentic acids. Sodium and potassium soaps can be made by direct saponification of the fats and oils or by the neutralization of the free fatty acids which are prepared in a separate manufacturing process.

(2) Synthetic organic detergents characterized by their high solubility in water, their resistance to precipitation by the constituents of hard water and their surface active and effective detergent properties, including:

(a) Anionic synthetic detergents (excluding true soaps): This class of synthetic detergents can be broadly described as the water-soluble salts, particularly the alkali metal (sodium, potassium, etc.) salts, of organic sulfuric reaction products having in the molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals. Important examples of the synthetic detergents which form a part of the preferred compositions of the present invention are the sodium or potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols produced by reducing the glycerides of tallow or coconut oil; sodium or potassium alkyl benzene sulfonates, in which the alkyl group in a straight or branched chain contains from about 9 to about 15 carbon atoms, especially those of the types described in United States Letters Patent Nos. 2,220,099 and 2,477,383; sodium alkyl glyceryl ether sulfonates, especially those ethers of the higher alcohols derived from tallow and coconut oil; sodium salts of sulfonated a-olefins containing 8 to 22 carbon atoms, e.g., those described in US. patent application, Ser. No. 561,397, filed June 29, 1966; sodium coconut oil fatty acid monoglyceride sulfates and sulfonates; sodium or potassium salts of sulfuric acid esters of the reaction product of .one mole of a higher fatty alcohol (e.g., tallow or coconut oil alcohols) and about three moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate with about four units of ethylene oxide per molecule and in which the alkyl radicals contain about 9 carbon atoms; the reaction product of fatty acids esterified with isethionic acid and neutralized with sodium hydroxide where, for example, the fatty acids are derived from coconut oil; sodium or potassium salts of fatty acid amide of a methyl taurine in which the fatty acids, for example, are derived from coconut oil; and others known in the art, a number being specifically set forth in United States Letters Patent Nos. 2,486,921, 2,486,922 and 2,396,278.

(b) Nonionic synthetic detergents: This class of synthetic detergents may be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a watersoluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

For example, a well known class of nonionic synthetic detergents is made available on the market under the trade name of Pluronic. These compounds are formed by condensing ethylene oxide Wth a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule which, of course, exhibits water insolubility has a molecular weight of from about 1500 to 1800. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a whole and the liquid character of the products is retained up to the point where the polyoxyethylene content is about 50% of the .total weight of the condensation product.

Other suitable nonionic synthetic detergents include:

(i) The polyethylene oxide condensates of alkyl phenols, e.-g., the condensation products of alkyl phenols having an alkyl group containing from about 6 to 12 'carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to to 25 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octane, or nonane, for example.

(ii) Those derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene-diamineprodu cts which may be varied in composition depending upon the balance between the hydrophobic and hydrophilic elements which is desired. For example, compounds containing from about 20% to about polyoxyethylene by weight and having a molecular weight of from about 5000 to about 11,000, resulting from the reaction of ethylene oxide groups with a hpdrophobic base constituted of the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight on the order of 2500 to 3000, are satisfactory.

(iii) The condensation product of aliphatic alcohols having from 8 to 18 carbon atoms, in either straight chain or branched chain configuration, with ethylene oxide, e.g., a coconut alcohol ethylene oxide condensate having from 10 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from 10 to 14 carbon atoms.

(c) Long chain tertiary amine oxides (nonionic detergents) corresponding to the following general formula, R R R N- O, wherein R contains an alkyl alkenyl or monohydroxy alkyl radical of from about 8 to about 18 carbon atoms from 0 to about 10 ethylene oxide moieties, and from 0 to 1 glyceryl moiety, and R and R contain from 1 to about 3 carbon atoms and from 0 to about 1 hydroxy group, e.g., methyl, ethyl, propyl, hydroxy ethyl, or hydroxy propyl radicals. The arrow in the formula is a conventional representation of a semi-polar bond. Examples of amine oxides suitable for use in this invention include dimethyldodecyl amine oxide, oleyldi(2-hydroxyethyl) amine oxide, dimethyloctylamine oxide, dimethyldecylamine oxide, dimethyltetradecylamine oxide, 3,6,9-trioxaheptadecyldiethylamine oxide, di.(2.-hydroxy.- ethyl) tetradecylamine oxide, 2-dodecoxy ethyl dimethy lamine oxide, 3-dodecoxy-2-hydroxy propyl di( 3-hydroxypropyl)-amine oxide, dimethylhexadecylamine oxide.

(d) Long chain tertiary phosphine oxides (nonionic detergents) corresponding to the following general formula RRR"P O wherein R contains an alkyl, alkenyl or monohydroxyalkyl radical ranging from 8 .to 18 carbon atoms in chain length, from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety and R and R" are each alkyl or monohydroxyalkyl groups containing from 1 to 3 carbon atoms. The arrow in the formula is a conventional representation of a semi-polar bond. Examples of suitable phosphine oxides are:

tetradecylmethyl-2-hydroxypropyl phosphine oxide,

oleyldimethylphosphine oxide, and 2-hydroxydodecyldimethylphosphine oxide.

(e) Long chain dialkyl sulfoxides containing one-short chain alkyl or hydroxy alkyl radical of 1 to about 3 carbon atoms (usually methyl) and one long hydrophobic chain which contains alkyl, alkenyl, hydroxy alkyl, or ketoalkyl radicals containing from about 8 to about 20 carbon atoms, from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety. Examples include:

octadecyl methyl sulfoxide, 2-ketotridecyl methyl sulfoxide 3,6,9-trioxaoctadecyl 2-hydroxyethyl sulfoxide dodecyl methyl sulfoxide oleyl 3-hydroxy propyl sulfoxide tetradecyl methyl sulfoxide 3-methoxytridecyl methyl sulfoxide 3-hydroxytridecyl methyl sulfoxide 3-hydroxy-4-dodecoxybutyl methyl sulfoxide (f) Ampholytic synthetic detergents can be broadly described as derivatives of aliphatic secondary and tertiary amines in which the aliphatic radical can be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. Examples of compounds falling within this definition are sodium 3-dodecylaminopropionate, sodium 3- dodecylaminopropane sulfonate, dodecyl beta alanine, N-alkyl-taurines such as the one prepared by reacting dodecylamine with sodium isethionate according to the teaching of US. 2,658,072, N-higher alkyl aspartic acids such as those produced according to the teaching of US. 2,438,091, and the products sold under the trade name Miranol and described in US. Patent 2,528,378.

(g) Zwitterionic synthetic detergents can be broadly described as derivatives of aliphatic quaternary ammonium, phosphonium, and sulfonium compounds, in which the aliphatic radicals can be straight chain or branched, and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. A general formula for these compounds is:

wherein R contains an alkyl, alkenyl, or hydroxy alkyl radical of from about 8 to about 18 carbon atoms, from to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety; Y is selected from the group consisting of nitrogen, phosphorous, and sulfur atoms; R is an alkyl or monohydroxy alkyl group containing 1 to about 3 carbon atoms; x is 1 when y is a sulfur atom and 2 when y is a nitrogen or phosphorous atom, R is an alkylene or hydroxy alkylene of from 1 to about 4 carbon atoms and Z is a radical selected from the group consisting of carboxylate, sulfonate, sulfate, phosphonate, and phosphate groups.

Other examples include:

4- [N,Ndi Z-hydroxyethyl -N-octadecylammonio butane-l-carboxylate;

5- [S-3-hydroxypropyl-S-hexadecylfonio] -3-hydroxypentanel-sulfate;

3- [P,P-diethyl-P-3,6,9-trioxatetracosanephosphonio] -2- hydroxypropanel-phosphate;

3- [N,N-dipropyl-N-3 -dodecoxy-2-hydroxypropylammonio] -propane-1-phosphonate;

3 N,N-dimethyl-N-hexadecylammonio) propane-1 -sulfonate, 3- (N,N-dimethyl-N-hexadecylammonio -2- hydroxypropane-l-sulfonate, 4- [N,N-di(2-hydroxyethyl) -N- 2-hydroxydodecyl) ammonio -butane-1- carboxylate, 3- [S-ethyl-S-(3-dodecoxy-2-hydroxypropyl)sulfonio]-propane-1-phosphate, 3- [P,P-dirnethyl- P-dodecylphosphonio]-propane-1-phosphonate, and S- [N,N-di 3-hydroxyp1'opyl) -N-hexadecylammonio] 2-hydroxypentane-1-sulfate.

Examples of compounds falling Within this definition are 3-(N,N-dimethyl-N-hexadecylammonio) propane-l-sulfonate and 3-(N,N-dimethyl-N-hexadecylammonio)-2-hydroxy propane-l-sulfonate which are especially preferred for their excellent cool water detergency characteristics.

The alkyl groups contain in said detergent surfactants can be straight or branched preferably straight and saturated or unsaturated as desired. The above list of detergent surfactants is exemplary and not limiting. Mixtures of the above detergent surfactants can be used.

The detergent compositions of this invention can be 10 prepared in any suitable physical form such as granules (e.g., either spray dried or mechanically mixed), tablets, pastes or liquids.

The compositions can contain particulate inorganic salts which are inert to the formula to act as fillers. Examples of such salts include sodium sulfate and sodium chloride.

Other minor ingredients can also be present in the compositions of this invention. Soil suspending agents such as sodium carboxymethylcellulose, optical brighteners, dyes, germicidal agents, suds depressants, and suds boosters, can each be added in amounts up to about 10% by weight of the composition.

The products of this invention can be used in aqueous solutions at levels of from about 0.05% to about 1.0% and when articles made from Zamac are contacted with these solutions there is considerably less corrosion than when similar compositions which do not contain the specific phosphonate corrosion inhibitor of this invention are used.

All parts, percentages and ratios herein are by weight unless otherwise specified.

The following examples demonstrate the desirable and unique performance of the corrosion inhibitors of this invention.

EXAMPLE I A spray dried granular detergent having the following composition was prepared by mixing the individual ingredients in a conventional manner with sufiicient water to form a detergent slurry and spray drying the slurry to remove excess moisture and to form detergent granules.

Percent Sodium straight chain alkyl benzene sulfonate having an average chain length of about 13 carbon A similar detergent composition was prepared which contained as an additional ingredient 0.3% or random octadecylphosphonic acid prepared by adding phosphorous acid to a random mixture of octadecenes using gamma radiation as a source of radicals. The random olefins were prepared by isomerizing l-octadecene with 10% iron pentacarbonyl at about 150 C. for approximately one hour. The added octadecylphosphonic acid replaced proportionate percentages of the ingredients in the first detergent composition.

The corrosiveness of the above two products was checked in a test using Zamac #3 test plates, which were approximately 1 inch by 4 inches by Ms inch in size. These tests plates were exposed to F. solutions of the detergent composition in distilled or tap hard water for six hours with agitation. The corrosion products were re moved by scrubbing with a brush having plastic bn'stles and the dried test plates were weighed to determine the weight loss due to corrosion. The results of these tests are tabulated below.

.(6) Hydrolyzed reaction product of l-octar EXAMPLES.P-ERCE NT BY WEIGHT OF THE COMPOSITION Oompo nent II III IV V VI VII VIII IX X XI XII XIII XIV Sodium tripolyphosphate Potassium ethane l-hydroxy-Llfltriphosphonate Sodium nitrilotriacetate Sodium ethane-l-hydroxyphosphonate Sodium random octadecyl phosphonate Potassium -octadecyl phosphonate. Random octadecyl phosphonic acid Sodium straight chain alkyl (Av.

Cm) benzene sulfonate Sodium tallow alkyl sulfate. 3-(N,N-dimcthyl-Ntallowalkylammonio)-2-hydroxypropane lsullonate The reaction product of S and C18 -olefin neutralized with sodium hydroxide Tallow alcohol ethylene oxide '(5 moles) reaction product 7 Coconut alkyldimethyl phosphine sulfoxide Coconut alkyl di 2-hydroxye thyl)- amine oxide Sodium silicate (SlOgZNQzO- 1.6) Benzotriazole Potassium pyrophosphate. Sodium perboratc. Sodium sulfate Coconut ammonia ami e Coconut diethanol amide Sodium carboxymethyl cellulose.

Potassium tolunesulfouate. 2

Water Form 1 Balance. 2 Granules. 3 Liquids.

The above compositions are useful as detergents at a level of about 0.1% in water detergents and are inhibited against the corrosion of Zamac.

EXAMPLE XV Aluminum plates were allowed to stand in an aqueous solution containing 0.35% of a detergent composition consisting of sodium tetrapropylene benzene sulfoate, 5 0% sodium tripolyphosphate, sodium sulfate and 5% of the below-named inhibitors. All percents herein are "by weight. The aluminum plates were exposed to the aqueous detergent solution for a period of three hours at 140 F. and pH 9.5. The water was not agitated. After the three-hour period, the aluminum plates were rinsed with water, the corrosion products removed with cone. HNO then rinsed with water and alcohol, dried and the weight l ss det r ed in mil i ams pe quare n meter. Results were obtained for both soft water and water containing hardness (equivalent to calcium carona o 7 ra ns pe g l on.

Wt. Loss in lugs/em.

Inhibitor .0 gin/gal.

(1) None (2) Oleylphosphonic acid.

debs cap-wow (4) .l -nonadecyl phosphonic acid i (5) ydrolyzed reaction product of 1-oct a- ,decene, PO13, acetic anhydride, and oxygen.

(This hydrolyzed reaction product is a mix-, ture of saturated and unsaturated octadecylphosphonic acids and saturated octadecylphosphates. Some of the saturated phosphoni'c acids contain bound chlorine)" *The saturated alkyl phosphonic acid content was greater thanBOZ, of the reaction product.

As can be seen from an inspection of the above results, the corrosion inhibitors of this invention (4, 5, 6,

7 and 9) are much more effective, especially in hard water, than similar compositions which are outside the scope of this invention (2, 3, and 8). Furthermore, rela-. tive to the control (1) the corrosion inhibitors are exceptionally advantageous. These compositions are all inhibited against the corrosion of Zamac #3.

When the following detergency builders are substituted for the sodium tripolyphosphate and/or sodium nitrilotriacetate in the above detergent compositions either wholly or in part so as to give, e.g., a 1:1 ratio, substantially equivalent results are obtained in that the detergent compositions containing these detergency builders are inhibited against the corrosion of Zamac #3: sodium, potassium, ammonium, monoethanol ammonium, diethanol ammonium, and triethanol ammonium salts of the following acids: ethylene diaminetetraacetic acid; N-(2- hydroxyetlhyl)-ethylenediaminetriacetic acid; N-(Z-hydroxyethyl)-nitrilodiacetic acid; diethylenetriaminepentaacetic acid; nitrilotriaceti-c acid; ethylene diphosphonic acid ethane-l-hydroxy-l,l-diphosphonic acid; ethane-1- hydroXy-l,l-diphosphonic acid; ethane-1,1,2-triphosphoni-c acid; ethane-Z-carboXy-l,l-diphosphonic acid, hydroxymethane-diphosphonic acid, carbonyldiphosphonic acid; ethane-l-hydroxy-1,1,24riphosphonic acid; ethane-Z-hydroxy-1,1, 2-triphosphonic acid, propane-1,1,3,3-tetraphosphonic acid; propane-1,1,2,3-tetraphosphonic acid; and propane-1,2,2,3-tetraphosphonic acid and potassium tripolyphosphate.

When in the above detergent compositions the following phosphonic corrosion inhibitors are substituted either wholly or in part, e.g., a 1:1 ratio, for the random octadecyl phosphonic acids substantially equivalent results are obtained in that the detergent compositions are inhibited against corrosion of Zamac #3: The corresponding tetracosane, tetradecane, pentadecane, heptadecane, nonadecane, eicosane, and docosane homologs of .the random octadecane phosphonic acids; the sodium, potassium ammonium, monoethanol ammonium, diethanol ammonium, and triethanol ammonium salts of the foregoing phosphonic acids; the following compounds and the sodium, potassium, ammonium, monoethanolammonium, diethanolammonium and triethanolammonium salts thereof:

lo-Nonadecylphosphonic acid;

Pentadecylbenzylphosphonic acid;

I Alkylbenzylphosphonic acid mixtures wherein the alkyl groups can be derived from (1) a mixture of propylene polymers, (2) olefins derived from cracked petroleum waxes, or (3) olefins displaced from Ziegler-type buildup reactions of ethylene, said alkyl groups ranging in size from 12 to 21 carbon atoms and averaging 14, 15, 16, Or 18 carbon atoms;

Hexadecylbenzylphosphonic acid wherein the hexadecyl group is derived from polymerized isobutylene;

Alkylbenzylphosphonic acids wherein the alkyl group is derived from a chlorinated kerosene fraction averaging 15, 16, 17, or 18 carbon atoms;

The mixture of 6-eicosenyl-4-phosphonic acid and vinyl octadecyl-4-phosphonic acid obtained by reducing the ketone obtained from the reaction between butyric acid anhydride and the allylic carbanion of l-hexadecene to the alcohol, conversion of the alcohol to the tosyl ester, alklation of dibutyl phosphonate anion with the ester, and hydrolysis of the resulting product;

The hydrolyzed reaction products of phosphorus trichloride, oxygen, and a mixture of olefins containing 18,

19, 20, or 22 carbon atoms and which can be derived from (I) cracked petroleum Waxes or (2) Ziegler-type build-up reactions of ethylene;

The mixture of octadecylphosphonic acids prepared by alkylating dibutyl phosphonate anion with the mixture of 2'- through 9-octadecyl sulfuric acids obtained by reacting l-octadecene with excess sulfuric acid at 0-l0 C. for about two to three hours and hydrolyzing the alkylated dibutyl phosphonate anion;

The mixture of phosphonic acids produced by first isomerizing the double bond of l-octadecene with aluminum chloride, adding sodium hypophosphite to the resulting olefins and oxidizing the resulting phosphinates to phosphonates with nitric acid;

The hydrolyzed reaction product of l-octadecene, phosphorus trichloride and oxygen;

, The hydrolyzed reaction product of l-octadecene, phosphorus trichloride, acetic anhydride and oxygen; and I The hydrolyzed reaction product of octadecane, phosphorus trichloride and oxygen, e.g., 1:1 or 2:1 ratios.

When in the above compositions the following organic detergents are substituted, either wholly or in part (e.g., a 1:1 ratio) for the said sodium alkyl benzene sulfonate having an average chain length of about 13 carbon atoms, substantially equivalent results are obtained in that the detergent composition is inhibited against the corrosion ofZamac #3:

(1,) The following anionic synthetic detergents wherein the cations are sodium, potassium, ammonium, monoethanolammonium, diethanolammonium, triethanolammoniurn cations. Salts of the higher fatty derived from 'palm oil, coconut oil, babassu oil, soybean oil, castor oil, tallow, whale oil, fish oils, grease, lard, resin acids from tall oil and/or naphthenic acids; alkyl sulfates wherein the alkyl group is derived from tallow or coconut oil; alkyl benzene sulfonates in which the alkyl groups contain 9, 11,312, 13 or 15 carbon atoms; alkyl glycidyl ether sulfonates derived from tallow or coconut oils; coconut fatty acid monoglyceride sulfates and sulfonates; salts of sulfuric esters of the reaction product of one mole of tallow or coconut oil fatty alcohols and 3 or v 4 ,moles of ethylene oxide; alkyl phenol ethylene oxideethe'r'sulfates containing 4 or 9 ethylene oxide moieties per molecule and in which the alkyl radical contains 9, 12, 1 3 or 15 carbon atoms; the neutralized reaction prod- ,uct of 'coconut fatty acids with isethionic acid; coconut fatty acid amide of methyl taurine salts;

(2) the condensation product of ethylene oxide with the condensation product of propylene oxide with propylene glycol, the ethylene oxide portion of the compound being 50% of the total weight of the compound and the total molecular weight of the compound being about 1700; the condensation product of alkyl phenols containing 9 or 12 carbon atoms in the alkyl group with 10, 15 or 20 moles of ethylene oxide per mole of alkyl phenol; the condensation product of ethylene oxide with the condensation product of propylene oxide and ethylene diamine wherein the product contains about 65% polyethylene oxide by weight and the total molecular weight of the compound is about 6000; the condensation product of coconut oil fatty alcohol and about 15 moles of ethylene oxide per mole of coconut alcohol;

dimethyldodecyl amine oxide, oleyldi(2-hydroxyethyl) amine oxide, dimethyloctylamine oxide, dimethyldecylamine oxide, dimethyltetradecylamine oxide, 3,6,9-trioxaheptadecyldiethylamine oxide, di(2-hydroxyethyl) tetradecylamine oxide, 2-dodecoxyethyl dimethylamine oxide, 3-dodecoxy-2-hydroxy propyl di(3-hydroxypropyl)-amine oxide, dimethylhexadecylamine oxide, dodecyldimethylph-osphine oxide, tetradecyldimethylphosphine oxide, tctradecylmethylethylphosphine oxide, 3,6,9-trioxaoctadecyldimethylphosphine oxide, cetyldnnethylphosphine oxide, 3-dodecoxy-2-hydroxypropyldi(2-hydroxyethyl)phosphine oxide, stearyldimethylphosphine oxide, cetylcthylpropylphosphine oxide, oleyl diethylphosphine oxide, dodecyldiethylphosphine oxide, tetradecyldiethylphosphine oxide, dodecyldipropylphosphine oxide, dodecyldi (hydroxymethyl) phosphine oxide, dodecyldi (2-hydroxyethyl) phosphine oxide, tetradecylmethyl-2-hydroxypropyl phosphine oxide, oleyldirnethylphosphine oxide, 2-hydroxydodecyldimethylphosphine oxide, octadecyl methyl sulfoxide, 3,6,9-trioxaoctadecyl 2-hydroxyethyl sulfoxide, dodecyl methyl sulfoxide, oleyl 3-hydroxy propyl sulfoxide, tetradecyl methyl sulfoxide, 3-methoxytridecyl methyl sulfoxide, S-hydroxytridecyl methyl sulfoxide, 3-hydroxy-4-dodecoxybuty1 methyl sulfoxide, sodium 3-dodecylaminopropionate, sodium 3-dodecylami nopropane-1-sulfonate, dodecyl-beta-alanine, N-alkyltaurines;

(3) N-higher alkyl aspartic acids, wherein the alkyl group contains about 12 carbon atoms;

and (5) mixtures thereof in, e.g., 1:1 ratios.

15 When the following German silver corrosion inhibitors are substituted either'wholly or in part (e.g., a 1:1 ratio) for the ben zotriazole in the above detergent compositions, substantially equivalent results are obtained in that the compositions do not discolor German silver to an objectionable degree; Z-aminobenzothiazole, 3-amino-1,2,4- triazole; ethylene thiourea; 3,5-dimethy1 pyrazole; adenin and mixt r t r o (cs What is claimed is: 1. Detergent compositions consisting essentially of: (1) from 1% to about 98% of the composition of a detergency builder selected from the group consisting of water-soluble amino polyacetate, tri olyphosphate and polyphosphonate detergency builders and mixtures thereof; (2) more than 0.05% and less than about 25% by weight of the total detergent composition of a corrosion inhibitor having the formula wherein R is selected from the group consisting of (1) a straight alkyl chain with the phosphorus atom attached to secondary carbon atoms on the chain, said straight chain alkyl radical containing from about 24 carbon atoms and (2) straight chain alkyl benzyl groups wherein the alkyl group contains from about 9 to about 18 carbon atoms and wherein Q is a water-solubilizing cation selected from the group consisting of hydrogen, alkali metal, ammonium, monoethanol-ammoniurn, diethanolamrnonium, and triethanolammonium cations;

(3) from to about 90% of other detergency builders selected from the vgroupconsisting of all ali metal p p o pha es .oi tbo o p a es c bo t o borates, hexaphosphates, sesquicarbonates and bicarbonates and mixturesthereof; and

(4) an organic detergentselected from the group consisting of nonionic, anionic, amp holytic and zwitterionic detergents and mixtures thereof in an amount Such t h ratio o tot-a si c sc ty bu s to organic detergent ranges from about 1:2 to about 10 1 and in an ount .nqtsteate n bo of the composition, said detergent composition being inhibited with respect to the cQrrosion of Zamac.

2. The detergent composition of claim 1 consisting essentially of:

(1) from about 1% to about 90% ,of the composition of a detergency'builder selected from the group consisting of water-soluble amino polyacetate, tripolyphosphate and polyphosphonate detergency builders andmixtures thereof;

(2) from 0% to about 1 5% by weight of the composition of an alkali metal silicate having a ratio of sio .M o of i em ab u 1 to abo 3-9.;

(3) more than 0.05% and less than about 25% by weight or the total 19 ers9 t com os t o a rosion inhibiting having the formula wherein R is el stssl from the: oup cons t ng of ('1) a straight alkyl chain radical with the phosphorous atom attached to secondary carbon atoms on the chain, saidstraight chain alkyl radical containing from about 12 to about 24 carbon atoms and (2) s a h 9 i a k b nz g u s whe ei the alkyl group contains from about 9 to about 18 carbon a oms;

(4) from 0% to about 1% of benzotriazole;

(5) from 0% to about 90% of other detergency builders selected from the group consisting of alkali metal pyrophosphates, orthophosphates, tetrabo-rates, perborates, hexaphosphates, sesquicarbonates and bicarbon-ates and mixtures thereof;

(6) an organic detergent in an amount such that the ratio of total detergency builders to organic detergent ranges from about 1:2 to about 10:1 and in an amount not greater than about 40% of the composition; and

(7) from 0% to about water.

3. The detergent composition of claim 2 wherein the detergency builder (1) is selected from the group consisting of the alkali metal, ammonium and substituted ammonium salts of the following acids wherein said substituted ammonium salts are selected from the group consisting of monoethanolammonium, diethanolarrnnonium and triethanolammonium salts: ethylenediaminetetraacetic acid; N-(Z-hydroxyethyl)-ethylenediaminetriacetic acid; N-(2-hydroxyethyl)-nitrilodiacetic acid; diethylenctriaminepentaacetic acid; 1,2-diamin-ocyclohexanetetraacetic acid; nitrilotriacetic acid; ethylene diphosphonic acid; ethane-l-hydroxy-l,l-diphosphonic acid; ethane- 1,1,2-triphos-phonic acid; ethane-Z-carboxy-1,1-diphosphonic acid; hydroxymethane-diphosphonic acid; carbonyldiphosphonic acid; ethane-l-hydroxy-l,1,2-triphosphonic acid; ethane-Z-hydr-oxy-i,1,2-triphosphonic acid; propane-1,1,3,3-tetraphosphonic acid; propane-1,1,23- tetraphosphonic acid; and propane-l, 2,2,3-tetraphosphonic acid and sodium and potassium tripolyphosphates.

4. The detergent composition of claim 1 wherein the corrosion (2) is a inhibitor randomly phosphonated octadecene.

5. The detergent composition of claim 2 containing as an organic detergent from about 10% to about 20% of a synthetic anionic organic detergent.

6. The detergent composition of claim 2 containing from 0.05% to about 2% of the phosphonate corrosion inhibiting compound (3) and from about 2% to about 10% of said alkali metal silicate.

7. The compositions of claim 1 wherein there is at least about 2% by weight of the total detergent composition of corrosion inhibiting compound, said phosphonate corrosion inhibiting compound being selected so that the straight alkyl chain (1) contains at least 18 carbon atoms and the straight chain alkyl benzyl .(2) groups contain at least 20 carbon atoms, the composition being inhibited against the corrosion of aluminum and German silver.

8. The compositions of claim 2 wherein there is at least about 2% by weight of the total detergent composition of corrosion inhibiting compound, said corrosi n inhibiting compound being selected so that the straight alkyl chain (1) contains at least 18 carbon atoms and the straight chain alkyl benzyl (2) groups contain at least 20 carbon atoms, the composition being inhibited against the corrosion of aluminum and German silver.

9. The detergent composition of claim 6 wherein the detergency builder is a mixture of water soluble tripolyphosphate and water soluble nitrilotriacetate in a molar ratio of from about 4:1 to about 1:4.

10. The detergent composition of claim 9 wherein the detergency builder is a mixture of sodium tripoly phost phate sodium nitrilotriacetate in a molar ratio of from about 3 :1 to about 1:3.

References Cited UNITED STATES PATENTS 2,618,604 11/1952 Schaeffer 252:- 2,765,279 10/1956 Nusselin 252-117 2,892,796 6/1959 McCune 252-137 3,001,945 9/1961 Drew et al. 252-152 3,054,821 9/1962 Rolih etal ,252 3s9 XR 3,159,581 12/1964 Diehl "252-9152 LEON D. ROSDOL, Primary Examiner.

S. E. DARDEN, Examiner. 

1. DETERGENT COMPOSITIONS CONSISTING ESSENTIALLY OF; (1) FROM 1% TO ABOUT 98% OF THE COMPOSITION OF A DETERGENCY BUILDER SELECTED FROM THE GROUP CONSISTING OF WATER-WOLUBLE AMINO POLYACETATE, TRIPOLYPHOSPHATE AND POLYPHOSPHONATE DETERGENCY BUILDERS AND MIXTURES THEREOF; (2) MORE THAN 0.05% AND LESS THAN ABOUT 25% BY WEIGHT OF THE TOTAL DETERGENT COMPOSITION OF A CORROSION INHIBITOR HAVING THE FORMULA 